Galactic nuclear bulge and the stellar content of spheroidal systems

Observational data on the Galactic bulge population are summarized and discussed, with a focus on the period 1965-1987, and their implications for S0 and elliptical galaxies are considered. Topics addressed include the previous observational history (Baade's concept of stellar populations, the pioneering photometry of Arp, spectroscopy of integrated bulge light, and surveys of the bulge), the characteristics of bulge giants (metallicity, IR colors, CM diagrams, ages and luminosities, and latitude dependence), and the use of bulge stars in stellar synthesis models. Particular attention is given to IRAS results and ground-based observations of IRAS sources, estimates of mass-loss rates, the 10-micron emission of the Galaxy and M31, surface-density and surface-brightness modeling, the inner and outer bulge regions, and balloon observations of the bulge. 171 references